| thermion | (n) an electrically charged particle (electron or ion) emitted by a substance at a high temperature |
| thermionic | (adj) of or relating to or characteristic of thermions |
| thermionic current | (n) an electric current produced between two electrodes as a result of electrons emitted by thermionic emission |
| thermionic emission | (n) the emission of electrons from very hot substances, Syn. thermal emission |
| thermionics | (n) the branch of electronics dealing with thermionic phenomena (especially thermionic vacuum tubes) |
